Looking for a little info on a oil pressure problem. or is it???

03 Silverado 6.0 gas 2x4 crew cab long bed

I run royal purple 5w 30 full synthetic oil.
I was in the mountains last weekend and the truck sat in 10-25 degree weather for about 3 days.

my engine pressure normally reads between 35-60ish according to gauge.

when I went out to start my truck the first time I payed close attention to make sure to watch the pressure gauge come up to normal. ( it did. no lag)

I let the car warm up for 20 minutes. Shut it off while I loaded the bags in the truck got in after about an hour.
When I started it this time the oil pressure gauge stayed at 0 and a chime sounded. The information center said engine oil pressure low.

I carefully listened to the engine and heard no unusual noises. So I revved the engine slightly and the gauge started to operate as usual.

It now does it every time I start the truck.
I took my chances and kept my ears open and drove 5 hours home.

I figured pressure sending unit. So I replaced it ($40 orileys) No change.

I changed the oil filter not the oil. Its only got about 1k on it. No change.

Now in stuck...

Any ideas?

Thanks Kevin

 

I have the same problem,my truck sound great but I have a low warning light and chims going off tried a new filte,what can I do?did you fix it?

 

If you drove it 5 hours the oil press is probably OK but to make sure I would hook up a mechanical gauge just to see what is going on. If all looks good its probably a gauge sticking. This is indicated by the fact it did it when cold. I had a gas gauge that got to where it wouldnt go down below 1/4 of a tank when cold. Got a refreshing walk one morning at 15 degrees.

 

Changed the oil filter,maybe it was a calaps, oil filter was good ,put on a mechanical pressure gage and had 3 psi at idle and 14 psi at 3000 rpms, changed oil pump and tha mechanical gage read the some 3 psi at idle and 14 psi at 3000 rpm and the crank bearing looked good,and the pick up seal looked good what to do?if the cam bearing where bad would I see damaege to the crank ?

 

Yes I agree with OW, what may be the problem is the gauge on the cluster may not be good. It is just a stepper motor in some and solely a rheostat in others. I had a car like this with the constant bad fuel measurement. I never got stranded because the light and the gauge worked independently of each other.

But if you add a mechanical gauge you can really see what your pressure is. Or you can have your cluster fixed.

 

Something weird going on here it cant be everybodys engines are worn out. Take a look at the post by jonhan,below.
This would be a good situation for a leak down test but I doubt if anyone has the equip or even knows what one is anymore.

 

Since your recomendations I have done oil flush in hopes that I will push anything out from the line but to no avail !!! Considering to take a look at the timing chain for any wear,running out of thinngs to do to it might have to change

 

There are complaints like this all over the place and they all seem to trace back to the 6.0 engine. I would check with a dealer to see if they have figured it out. The tech departments arent that great but some time someone at a dealership will stumble on a solution and relay the info to them, then some suit throws his chest out and gets a bonus for it.

 

I have had Similar problems with oil pressure being low until warmed up. I use royal purple in all my vehicles also. You might want to check the pickup tube/ screen. I've had two Chevy vehicles with bad o-rings on the pickup tube go bad causing low suction to the pump. Just a thought!!

 

There is also a oil filter bypass valve to protect the engine and the one in your truck may be stuck open.